OMAP: DSS2: enable VDDS_DSI when using DPI

It looks like on OMAP3 some DSS pins need VDDS_DSI to function properly.

This has not been confirmed from TI, but looking at figure 15-1 "Display
subsystem highlight" from the TRM, some data pins come near the DSI and SDI
blocks. This is not very hard evidence, but the fact remains that with the
power on, pixels are ok, and with the power off, pixels are not ok.

It may also be that VDDS_SDI is needed to power some pins, but as normally
both VDDS_SDI and VDDS_DSI come from the same power source, this hasn't
been shown.

It seems that a single driver can only get a regulator once. This patch
solves it by getting all the required regulators in one place, and from
which the submodules then get the regulators they need.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@nokia.com>
diff --git a/drivers/video/omap2/dss/dpi.c b/drivers/video/omap2/dss/dpi.c
index 2d71031..69ce31a 100644
--- a/drivers/video/omap2/dss/dpi.c
+++ b/drivers/video/omap2/dss/dpi.c
@@ -25,7 +25,10 @@
 #include <linux/kernel.h>
 #include <linux/clk.h>
 #include <linux/delay.h>
+#include <linux/err.h>
 #include <linux/errno.h>
+#include <linux/platform_device.h>
+#include <linux/regulator/consumer.h>
 
 #include <plat/display.h>
 #include <plat/cpu.h>
@@ -34,6 +37,7 @@
 
 static struct {
 	int update_enabled;
+	struct regulator *vdds_dsi_reg;
 } dpi;
 
 #ifdef CONFIG_OMAP2_DSS_USE_DSI_PLL
@@ -166,21 +170,27 @@
 		goto err1;
 	}
 
+	if (cpu_is_omap34xx()) {
+		r = regulator_enable(dpi.vdds_dsi_reg);
+		if (r)
+			goto err2;
+	}
+
 	dss_clk_enable(DSS_CLK_ICK | DSS_CLK_FCK1);
 
 	r = dpi_basic_init(dssdev);
 	if (r)
-		goto err2;
+		goto err3;
 
 #ifdef CONFIG_OMAP2_DSS_USE_DSI_PLL
 	dss_clk_enable(DSS_CLK_FCK2);
 	r = dsi_pll_init(dssdev, 0, 1);
 	if (r)
-		goto err3;
+		goto err4;
 #endif
 	r = dpi_set_mode(dssdev);
 	if (r)
-		goto err4;
+		goto err5;
 
 	mdelay(2);
 
@@ -188,22 +198,25 @@
 
 	r = dssdev->driver->enable(dssdev);
 	if (r)
-		goto err5;
+		goto err6;
 
 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 
 	return 0;
 
-err5:
+err6:
 	dispc_enable_lcd_out(0);
-err4:
+err5:
 #ifdef CONFIG_OMAP2_DSS_USE_DSI_PLL
 	dsi_pll_uninit();
-err3:
+err4:
 	dss_clk_disable(DSS_CLK_FCK2);
 #endif
-err2:
+err3:
 	dss_clk_disable(DSS_CLK_ICK | DSS_CLK_FCK1);
+err2:
+	if (cpu_is_omap34xx())
+		regulator_disable(dpi.vdds_dsi_reg);
 err1:
 	omap_dss_stop_device(dssdev);
 err0:
@@ -232,6 +245,9 @@
 
 	dss_clk_disable(DSS_CLK_ICK | DSS_CLK_FCK1);
 
+	if (cpu_is_omap34xx())
+		regulator_disable(dpi.vdds_dsi_reg);
+
 	dssdev->state = OMAP_DSS_DISPLAY_DISABLED;
 
 	omap_dss_stop_device(dssdev);
@@ -251,6 +267,9 @@
 
 	dss_clk_disable(DSS_CLK_ICK | DSS_CLK_FCK1);
 
+	if (cpu_is_omap34xx())
+		regulator_disable(dpi.vdds_dsi_reg);
+
 	dssdev->state = OMAP_DSS_DISPLAY_SUSPENDED;
 
 	return 0;
@@ -258,11 +277,19 @@
 
 static int dpi_display_resume(struct omap_dss_device *dssdev)
 {
+	int r;
+
 	if (dssdev->state != OMAP_DSS_DISPLAY_SUSPENDED)
 		return -EINVAL;
 
 	DSSDBG("dpi_display_resume\n");
 
+	if (cpu_is_omap34xx()) {
+		r = regulator_enable(dpi.vdds_dsi_reg);
+		if (r)
+			goto err0;
+	}
+
 	dss_clk_enable(DSS_CLK_ICK | DSS_CLK_FCK1);
 
 	dispc_enable_lcd_out(1);
@@ -273,6 +300,8 @@
 	dssdev->state = OMAP_DSS_DISPLAY_ACTIVE;
 
 	return 0;
+err0:
+	return r;
 }
 
 static void dpi_set_timings(struct omap_dss_device *dssdev,
@@ -388,8 +417,16 @@
 	return 0;
 }
 
-int dpi_init(void)
+int dpi_init(struct platform_device *pdev)
 {
+	if (cpu_is_omap34xx()) {
+		dpi.vdds_dsi_reg = dss_get_vdds_dsi();
+		if (IS_ERR(dpi.vdds_dsi_reg)) {
+			DSSERR("can't get VDDS_DSI regulator\n");
+			return PTR_ERR(dpi.vdds_dsi_reg);
+		}
+	}
+
 	return 0;
 }